1. Field of Invention
This invention relates to a speaker enclosure, specifically to a speaker enclosure designed to improve sound through controlling an air pressure differential across the front and rear of a speaker cone.
2. Description of Prior Art
A variety of speaker enclosures are known in the prior at. The invention in U.S. Pat. No. 5,197,103 to Hayakawa discloses a low sound loudspeaker system consisting of an acoustic pipe extending from the back side of a loud speaker unit, an air chamber provided at the front side of the loud speaker unit, and a bass reflex port provided within the air chamber. The acoustic pipe communicates with the air chamber via the aperture of the acoustic pipe.
The invention in U.S. Pat. No. 5,514,841 issued to Rochon discloses a reflex compression valve--divided chamber sr cabinet. The Rochon cabinet contains ports located frontally and rearwardly within the speaker cabinet. The invention in U.S. Pat. No. 4,440,260 issued to Jacobson discloses a bass reflex enclosure or cabinet which achieves an acoustically dead front plate. In the Jacobson invention, the loud speak unit is mounted in an opening so that an annular slot is provided around the speaker unit and utilized as a bass-reflex port arranged coaxially with the speaker unit.
The invention disclosed in U.S. Pat. No. 5,173,575 issued to Surukawa comprises a compact acoustic apparatus in which a vibrator is arranged in a Helmholtz resonator having a resonance port and is driven to radiate the resident acoustic waves.
The invention disclosed in U.S. Pat. No. 5,517,573, to Polk, et al, discloses a vented loud speaker system with a port opening in a spear cabinet, and disk or baffle plates mounted at a pre-determined distance to and concentric to the port opening resulting in a vented system.
The invention disclosed in U.S. Pat. No. 5,327,504 issued to Hobelsberger discloses a loud speaker system using closed housing. The housing of the devices are divided by inner walls into two or three inner chambers. One inner chamber adjoins the membrane of the loud speaker and adjoining this inner chamber a membrane is built into an opening of an inner wall. Movements of the inner membrane caused by pressure changes in the chamber are servo supported by an inner electrodynamic transducer whose membrane lies parallel behind the other membrane. The supporting movements are caused by a control which tries to hold constant the distance between the two inner membranes.
The invention disclosed in U.S. Pat. No. 5,461,676 to Hobelsberger discloses devices to improve low frequency sound reproduction in loud speaker systems utilizing acoustically closed loud speaker housings.
The invention in U.S. Pat. No. 4,714,133 to Skaggs discloses a method for improving overall efficiency and quality in sound reproduction systems by providing a system which establishes positive phase control over resident sound characteristics by utilizing acoustically coupled drives. Conventional cone drivers are acoustically coupled to both air and the materials from which the enclosure of the speaker is formed by optimizing existing atmospheric pressure differentials and induced audio vibration readily available within these structures. The coupling is obtained for the use of acoustical resonator structures placed within a speaker enclosure and through particular distribution of mass in the enclosure and in the materials.
The invention disclosed in U.S. Pat. No. 4,008,374 to Tiefenbrun discloses a bass unit for a loudspeaker system having a pair of loudspeakers mounted one behind the other in a casing to define a chamber of air. The loudspeakers are operated in phase with one another so that the pressure of air in the chamber remains substantially constant allowing the forward loud speaker to operate in ideal conditions. The cabinet also includes a curtain of absorbent material in the chamber to absorb changes in sound pressure.
The invention disclosed in U.S. Pat. No. 5,374,124 to Edwards discloses a loud speaker system including electronic filtering to increase high frequency components beyond the audible range as well as a multi-compound Isobarik system having a single internal baffle within the loud speaker enclosure to allow acoustical drivers operating with similar frequency ranges to be physically located anywhere within the enclosure without limitation due to internal air pressure variations. Enclosure resonance is reduced by use of cylindrical prisms as structured elements. This disclosure further reveals an enclosure formed by a plurality of sub-enclosures.
None of the inventions in the prior art disclose a loud speaker system having a primary channel located at the rear of a loud s r in open communication with a convergence channel of diminishing cross-section which is open to ambient air.